1. Field of the Invention
This invention relates to a vehicle heating system of simple yet highly effective design which has numerous advantages including greater heat generation, longer heater core life and prolonged life for the vehicle transmission system. More particularly, it is concerned with a vehicle heating system wherein transmission fluid is diverted from its cooling route and circulated through the heater core for heating the vehicle passenger compartment.
2. Description of the Prior Art
Most vehicles, particularly automobiles, circulate engine coolant through a heat exchanger for the purpose of heating the passenger compartment. The problem with such heating systems is that when the engine coolant is diverted from the radiator cooling route to the heater core, the chemical characteristics of the coolant cause corrosive and pollutive problems as it is circulated. In particular, the corrosive nature of typical coolants such as ethylene glycol results in leakage of the coolant out of the heater core, often into the passenger compartment resulting in frequent, costly heater system repairs and unpleasant and potentially unhealthy circumstances in the passenger compartment. Accordingly, the prior art points out the need for a system which can be easily retrofitted and yet provide a relatively noncorrosive liquid for heat transfer.
A number of systems for heating passenger compartments have been proposed in the past. In general, however, these units have not met the above-described needs. Patents illustrating these prior units include: U.S. Pat. Nos. 1,895,503, 2,531,019, 4,069,972, 4,136,824, 4,192,456, 4,346,839, 4,352,455, 4,370,956, 4,371,112, 4,368,735, 4,407,449, 4,432,493, 4,434,934, and 4,487,364.